Building Your Own AR-15: A Step-by-Step Guide

Building Your Own AR-15: A Step-by-Step Guide

Building your own AR-15 isn’t just a hobby, it’s a way to create a rifle tailored to exactly how you shoot. Whether you're piecing together an affordable build for home defense or creating a competition ready beast, the process is super rewarding. Plus, you can pick every component to match your preferences and performance needs.

Let’s walk through the key components and help you create your dream AR-15 from scratch, with some solid product recommendations along the way!

1. Upper Receiver

The upper receiver is the foundation of your AR-15, and it plays a big role in how the rifle performs. The upper houses your bolt carrier group, barrel, and other crucial parts, so quality matters here. When you invest in a Bravo Company Manufacturing (BCM) upper, you're getting unmatched durability and precision. BCM uppers are designed for tactical applications, so they can handle anything from range days to real life scenarios.

Want to check out some solid complete BCM uppers? You can find a range of options at BCM Upper Receivers.

2. Barrel and Gas Blocks

The barrel has one of the biggest impacts on your AR-15’s accuracy. If you want consistent performance and long-term reliability, chrome-lined barrels are a go-to. Aero Precision offers some great 16” options, while Ballistic Advantage and BKF are other trusted names for top tier barrels. When you’re picking out a barrel, keep in mind the twist rate, length, and material, as they all influence your shooting experience.

Gas Block

The gas block regulates gas flow from the barrel to the gas system, affecting reliability and cycling. Consider these types:

• Low-Profile Gas Block: Ideal for builds with free-floating handguards, ensuring a clean and streamlined appearance.
• Adjustable Gas Block: Allows you to fine-tune gas flow, which is especially useful for suppressor use to reduce blowback.

Gas Tube

The gas tube carries gas from the gas block to the bolt carrier group, playing a crucial role in the cycling process. Make sure to choose the right length based on your barrel:

• Pistol Length: Typically used for barrels 14.5 and shorter
• Carbine Length: Typically used for barrels 16 inches and shorter.
• Mid-Length: Best for barrels 16-20 inches, providing a smoother cycling action.
• Rifle Length: Used for barrels longer than 20 inches, ensuring adequate gas pressure for reliable cycling.

Pro Tip: A 16" barrel is super versatile, it’s a good balance for both home defense and range use.

Find high-quality barrels like Aero Precision and Ballistic Advantage barrels at Barrel Selection

3. Bolt Carrier Group (BCG)

The BCG is the workhorse of your AR-15, it’s what cycles the action and makes everything run smoothly. For top reliability and performance, look for a high quality BKF bolt carrier groups. These companies are known for creating rugged, high-quality BCGs that won’t let you down when it counts. A solid BCG can also reduce malfunctions, which is key for a dependable build.

Pro tip:  A high-quality coating on a BCG makes function and cleaning that much better.  Some of the most popular a Titanium Nitride and DLC coated bolts.  

Ready to upgrade? You can grab BCGs from BKF, or right here at Bolt Carrier Group.

4. Handguards

Your handguard is where you’ll mount all those accessories (think optics, lasers, grips, and more). Free-floating handguards are the best choice here, they increase accuracy by eliminating barrel contact and give you tons of room for attachments. Brands like Aero Precision, and BKF make high-quality, lightweight handguards that look great and perform even better.

Bonus: Free floating handguards also allow for more precise shooting because there’s no added pressure on the barrel.

Find top notch handguards at AR15 handguards.

5. Trigger

Now let’s talk triggers. A good trigger can be the difference between a smooth, precise shot and a frustrating experience. The Geissele Super Dynamic 3 Gun Trigger is a fan favorite for its clean break and short reset. It’s perfect for competition shooters or anyone looking for a smoother shooting experience. Plus, it’ll take your AR-15’s precision to the next level.  Another very popular option are drop in ready trigger sets.  For those not looking for the complicated process of installing a standard trigger, drop ins such as the Rise Armament RA 524 or James Madison Tactical EVO take out all the hassle and make for super simple installs.  Best part, you get top tier performance for half the cost.

Want to upgrade your trigger? Check out these triggers:  AR15 triggers.

6. Lower Receiver

You can't have an AR-15 without a lower receiver, this is what ties it all together. Your lower houses the fire control group (aka the trigger), magazine well, and buffer assembly. Aero Precision makes high-quality lowers that are affordable yet highly durable. When combined with a quality upper, you’ll have the foundation for a reliable, high-performing AR-15.

Explore Aero Precision lowers at AeroPrecision.

7. Choosing a High-Quality Charging Handle

The charging handle is often overlooked in AR-15 builds, but choosing the right one can significantly improve your rifle's performance, especially when shooting suppressed or under heavy use. If you plan to run your AR-15 suppressed, the Breek Arms Sledgehammer AR-15 Gas Blocking Charging Handle is one of the best options for gas busting. This charging handle is specifically designed to redirect gases away from the shooter’s face, making it ideal for suppressor use. Another premium option is the Radian Raptor ambidextrous charging handle, known for its durability and smooth operation. It also excels at managing gas blowback, making it a popular choice for suppressed setups.

 Pro Tip:

If you're building an AR-15 with suppressor use in mind, opt for a charging handle with gas busting features like the Breek Arms Sledgehammer or the Radian Raptor. Not only will these reduce blowback and protect your face from excess gas, but they'll also enhance the overall shooting experience by making your rifle more comfortable and reliable to shoot suppressed.

Check out this great selection of charging handles:  Charging handles

8. Buffer Tubes & Springs

The buffer system is essential for recoil management and proper cycling. Choose components that fit your rifle's intended use.

• Mil-Spec Buffer Tube: Standard for most AR builds, offering durability and compatibility with Mil-Spec stocks.
• Enhanced Buffer Tube: Offers thicker walls and better corrosion resistance, ideal for heavy-duty or precision builds.
• Buffer Springs: A standard carbine spring works for most builds, but a flat-wire spring reduces noise and improves cycling, especially for suppressed rifles. 
• Castle Nuts: A small but crucial part of your build, this little piece secures your lower receiver to your stock assemble.
• Castle Nut End Plate: The end plate sits between the lower receiver and the castle nut, locking the buffer tube in place and provides a spot for staking.  

9. Lower Parts Kits

A quality lower parts kit (LPK) ensures all the essential small parts fit and function correctly.

• Standard LPK: Contains all necessary components, including pins, springs, the fire control group, and a grip, making it a great budget-friendly option.
• Enhanced LPK: Comes with upgraded components like a smoother trigger and stronger pins and springs, improving reliability and performance. 

10. Pistol Grips

A good pistol grip improves handling and comfort, especially during extended use.

• Die Free Co. Kung Fu grip Ergonomic and widely liked for its durability and natural fighting posture.
• Magpul MOE K2: Provides a soft, rubberized feel for better grip and control, ideal for shooters seeking extra comfort during long sessions. 

Pro Tip:

If you're building a suppressed or precision rifle, upgrading to a flat-wire buffer spring will reduce noise and improve cycling reliability. Additionally, investing in an enhanced LPK ensures better performance and durability in critical components.  And do not overlook your pistol grip.  An ergonomic grip will greatly improve comfort and control.

Stocks: Pistol Braces & Regular Options

Choosing the right stock or pistol brace is crucial for comfort and control on your AR-15.

Pistol Braces

• SB Tactical SBA3: Adjustable and lightweight, offering excellent support for AR pistols.
• SB Tactical SBA5: Compact and retractable, ideal for close quarters use.

Regular Stocks

• Magpul DT Stock: Durable and simple, known for its reliability and tight fit.
• Magpul CTR Stock: Snag free and features a friction lock for added stability.
• Magpul PRS light Stock: Offers enhanced comfort and cheek weld for precision shooting.

Pro Tip:

When selecting a stock or brace, consider how you plan to use your AR-15. For a pistol build, an adjustable brace like the SB Tactical SBA3 provides versatility. For a rifle build, the Magpul CTR stock enhances stability and comfort, making it ideal for longer shooting sessions.

Putting it All Together

Building your AR-15 takes a bit of time and effort, but it’s 100% worth it. You’ll get a rifle that’s tailored to your exact needs, from precision shooting to tactical use. Here’s a quick summary of what you’ll need:

• Upper Receiver: BCM 
• Barrel: Aero Precision or BKF
• Gas Block and Tube:  Aero Precision
• Bolt Carrier Group: BKF
• Handguards: Aero Precision or BKF
• Trigger: JMT EVO
• Lower Receiver: Aero Precision
• Charging Handle: Breek Arms Sledgehammer
• Buffer Tubes and Springs: Mil Spec buffer and spring
• LPK's (lower parts kits): Standard LPK
• Pistol Grips: Kung Fu Grip
• Stocks: Magpul CTR

You can mix and match parts based on your budget and how you plan to use the rifle. Just make sure to use high quality components, and you’ll have a build that performs as well (or better!) than a factory rifle.

Conclusion

Building your AR-15 from scratch lets you customize your rifle exactly how you want. By carefully selecting each part, like a BCM upper or a Geissele trigger, you can ensure your rifle delivers top-tier performance. Whether you’re building an AR-15 for home defense, range use, or competition, the right parts will help your rifle excel in any situation.

Ready to get started? Check out TheFreedomWarehouse.com for everything you need.